In 2005, average residential energy rates across the USA ranged from about 6 to nearly 16 cents per kilowatt hour depending on where you lived.

Average retail and commercial energy rates have increased roughly 30% since 1999 and the upward trend will likely continue.

The FSEC has conducted a study to examine how efficient a solar system is in the USA.

The study accounted for factors such as the temperature effect on the cells, the amount of sun peak hours in various regions, and the efficiency to convert solar derived energy from DC to AC.

In general, solar photovoltaic systems sized between 1 to 5 kilowatts are usually sufficient to meet the electricity needs of most homes.

One advantage of grid-tied systems is that you can use solar PV to supplement or offset some of your electricity needs.

To get started, it's good to have a sense of how much electricity you use.

You'll have a better point for comparison if you find out how many kilowatt hours (kWh) you use per day, per month, per year. Your utility bill should include that information.

Many states and local jurisdictions offer rebates, tax credits and other types of incentives to homeowners for installing photovoltaic and solar domestic water systems.

To view a comprehensive database of the incentives available for renewable energy visit http://www.dsireusa.org

The cost for a solar PV system will depend on the size of the system, your electricity rate, the amount of kilowatt hours you expect to generate, and the state/local rebates/tax credits that may be available.

A more accurate assessment can be made by San Diego Solar Green.